From this point, it heads northwest, serving as the southern terminus of State Highway 1 and the main street of Mannsville.

US-177 continues north into western Garvin County, serving as the eastern terminus of SH-29 and crossing SH-19 in Stratford.

The three highways then cross the Canadian River into Pottawatomie County, where they meet SH-39 at a four-way stop in Asher.

Just west of Warwick, it meets SH-66 (old Route 66), and then passes under Interstate 44 (the Turner Turnpike), with no interchange.

US-177 then continues north, connecting to the town of Carney via SH-40A, the shortest state highway in Oklahoma.

It then passes through the county seat, Stillwater, the home of Oklahoma State University.

North of Stillwater, it serves as the western terminus of the Cimarron Turnpike Spur.

Farther north, in Noble County, it crosses US-64 and the mainline of the Cimarron Turnpike.

It serves Ponca City, where it begins a wrong-way concurrency with its parent, US-77, as well as US-60 (which is signed the "correct" direction).

Only 4 mi (6.4 km) north of the state line, US-177 ends at US-81 in downtown South Haven, Kansas.